So I just (for the first time) replaced all the rubber components in my 1950 bathroom sink which had leaked. Next the shower/bath, wall mounted original hot and colds. There are two baths, both drip. Upstairs is "fairly" modern having large base metal chrome plated hot and cold handles. After getting a puller to get them off (where welded with calcium to the stem) I realized the only way to get the stem out and replace the washer is to remove the metal cover that sits against the wall. Which is conveniently grouted to the wall tile. How do I remove that without damaging the tile and perhaps the metal component. In the downstairs bath these cup shaped covers are actually porcelain...again grouted to the wall....